460643 - Slow scrolling speed in 3.1 builds after 10/17/2008

Status: VERIFIED FIXED

(Core :: Widget: Gtk, defect)

Description

[Brad Jackson]

User-Agent:       Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.1b2pre) Gecko/20081017 Firefox/3.1b2pre
Build Identifier: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.1b2pre) Gecko/20081017 Firefox/3.1b2pre

In my builds of 3.1b2pre after around 10/17/2008 5:30 CDT, a behavior similar to smooth scrolling began even with general.smoothScroll set to false. Dragging the scroll bar thumb rapidly up or down and releasing the mouse button results in slow scrolling. Resizing the bookmarks sidebar results in intolerably slow resizing.

Reproducible: Always

Steps to Reproduce:
1. Turn the smooth scrolling pref off
2. Drag scrollbar thumb rapidly up or down, or resize bookmarks sidebar

Actual Results:  
Scrolling speed is slow and window refresh on resizing is extremely sluggish

Expected Results:  
There should be no smooth scrolling anywhere when the pref is off. Resizing the sidebar should be fast.

Comment 1

[nulldomain]

I can also confirm this.  

Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.1b2pre) Gecko/20081018 Firefox/3.1b2pre

Comment 2

[Ilja Sekler]

I don't see any impact on scrolling web pages. But dragging a splitter like that of the sidebar or a horizontal one of Adblock+ has become painfully slow. This belongs in "Core", not in "Firefox" and is a major regression, which renders also GUI of Sunbird and Thunderbird almost unusable.

Comment 3

[Elmar Ludwig]

Confirming, I see this as well. Need to check the cause of this regression.

Comment 4

[Elmar Ludwig]

I can easily reproduce this when scrolling long FTP listings like the one on ftp://ftp.mozilla.org/pub/firefox/nightly/

Regression range:

 2008-10-17-03 - ok
 2008-10-18-02 - shows lag on scrolling

Maybe bug 459780?

Comment 5

[Elmar Ludwig]

As noted in comment #2, this makes pane resizing almost ununable, nominating for blocking.

Comment 6

[Brad Jackson]

I backed out the patch from bug 459780 and verified that is the cause of the scrolling and resizing slowness.

Comment 7

[Reed Loden [:reed]]

(In reply to comment #6)
> I backed out the patch from bug 459780 and verified that is the cause of the
> scrolling and resizing slowness.

Thanks, backed out. If the next build after the backout looks ok, please mark this fixed.

Comment 8

[nulldomain]

Everything's fine for me on trunk after the backout from bug 459780.

Comment 10

[Elmar Ludwig]

Verified fixed in Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.1b2pre) Gecko/20081020 Minefield/3.1b2pre ID:20081020020323